Vented hammermill crusher

Abstract

An enclosed hammermill crusher having a closed-loop vent is described. The crusher-enclosure has an upper vent opening in the housing above the hammers where the hammer direction is upward, said vent opening communicating with a closed-loop vent duct. The lower part of the crusher housing is contiguous with a crushed particulate collector which has sloping sides and a small discharge opening cummunicating with a discharge conduit. The lower end of the vent duct connects to the discharge conduit near the collector discharge opening, preferably at about right angles to the discharge conduit. The inlet opening for aggregate material in the top of the housing is above the hammers where said hammers have a downward direction.

I claim: 
     
       1. A vented hammermill crusher comprising: a. a housing and rotary crusher means having an upper inlet opening above that portion of the rotary crusher means where the crusher direction is downward, a vent opening above that portion of the rotary crusher means where the crusher direction is upwards,   b. a crusher particulate collector having a large upper opening communicating with the housing bottom, said collector having sloping sides and a small discharge opening,   c. a discharge conduit communicating with the discharge opening of the collector, said conduit having substantially the same angle as the collector wall relative to the horizontal and having an opening therein,   d. a vent duct external to said housing connecting said vent opening of the crusher housing and the opening in the discharge conduit, said vent duct connecting to said discharge conduit at an angle of about 90° to the discharge conduit sidewall.   
     
     
       2. The vented crusher of claim 1 wherein said collector sloping sides have a slope of from about 45° to 60° to the vertical. 
     
     
       3. The vented crusher of claim 1 wherein said upper opening and said vent opening are separated by a deflector plate. 
     
     
       4. The vented crusher of claim 1 wherein said crusher housing has sidewalls and a top cover, said top cover having said vent opening therein closely adjacent the crusher means. 
     
     
       5. The vented crusher of claim 1 wherein said deflector plate is disposed at an angle of about 60° to about 70° with respect to the top cover of said housing 
     
     
       6. The vented crusher of claim 1 wherein said vent opening communicates with a vent housing having an angularly disposed delfector plate and vent duct extending from said vent housing in a substantially straight line for a short distance. 
     
     
       7. The vented crusher of claim 1 wherein said vent duct has a wall in common with an outer wall of said crusher housing.